Above all, a generator. 150,000 people in my city were without power for 8 days last winter, due to a 10 minute windstorm.
If you don't overstock, your tank should be good for 8 hours with no circulation.
There are also battery-powered air pumps by Plax, which you can get from Petco or Amazon. Keep a couple, with batteries, on hand.
Don't worry about dropping temperatures: I got my tank through the 8 day blackout without a generator by 1. letting temperature ride at 61.8, which slowed chemical processes, including decay from inverts I did lose. 2. getting up on a chair every 4 hours and dipping and pouring water in to sub for the batteried bubblers I DIDN"T have. You pour from a gallon pitcher enough water to total your tank volume. Maintaining the room temperature was the hardest battle. We lived in one room with insulated curtains on the windows and sheets hung in doorways...
Get a generator. Spendy, but so much easier.